Variable-drive mechanism.



S. B. GRAY, DEGD.

B. S. GRAY, BXEOUTOB. VARIABLE DRIVE MECHANISM.

APPLICATION FILED APR. 6. 1906.

Patented June 1. 1909.

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B. S. GBA'Y, EXEGUTOB, T VARIABLE 1mm Mnommsm. APPLICATION FILED-AYE. 6.1905.

Patented June 1. 1909.

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UNITED STATES PATENT OFFICE.

STEPHEN B. GRAY, OF JACKSONVILLE, ILLINOIS; BARTLETT S. GRAY EXEOUTOR orSAID STEPHEN B. GRAY, DEoEAsED.

VARIABLE-DRIVE MECHANISM.

Specification of Letters Patent.

Patented June 1, 1909.

To all whom it may concern:

Be it known that I, STEPHEN B. GRAY, a resident of Jacksonville, in thecounty of Morgan and State of Illinois, have invented certain new anduseful Improvements in Variable-Drive Mechanism, of which the followingis a full, clear, and exact description.

The invention relates to variable drivemechanism and designs moreparticularly to provide an improved construction of variable pulley, andimproved mechanism for relatively adjusting the cooperating pulleys of adriving mechanism.

The invention consists in the several novel features hereinafter setforth and more particularly defined by claims at the conclusion hereof.

In the drawings: Figure 1 is a plan view of a variable drive-mechanismembodying the preferred form of the invention, a portion of the beltbeing broken away. Fig. 2 is a view in side elevation of the cams forshifting the adjusting levers, the cross-bars whereon they are supportedbeing shown in section. Fig. 3 is a section on line 33 of Fig. 1. Fig. 4is a side elevation, the supporting-frame being shown in section. Fig. 5is a detail section on an enlarged scale, taken on line 5-5 of Fig. 6,some of the levers whereby the periphery-sections are supported beingomitted. Fig. 6 is a view in vertical section of one of the pulleys.Fig. 7 is a central longitudinal Section on line 77 of Fig. 6.

The variable drive mechanism usually comprises a pair of pulleys whichare respectively mounted on shafts from one of which motion is impartedto the other. These pulleys are of like construction and are providedwith variable or adjustable rims. ley comprises abody or support whichserves as a guide for the rim-sections and whereby the sections areconnected together for revolution. The body or support is formed ofsections 20 and 21secured togetherbybolts 23. One of the sections isprovided with a hub 22 whereby it can be secured to its shaft. Eachsection of the body comprises a side 24 having radial slots 25 thereinand an inwardly extending web or portion 26 and a central portion 27.The rim or drive-face of the pulley consists of a plurality of sections28 having their ends held in slots 25 of the body, so the sections willrevolve with said body. The rim-sections are adjustable to vary the sizeof the rims or working-face of the pulley the wheel-shaft.

The pul-.

and are supported in parallel relation by a pair of links 29 and 30,respectively pivoted near the ends of each section as at 31 and 32. Eachof said links has its outer ends bifurcated to receive the rim-sectionto which it is pivoted and the links of a bar are slightly offset withrelation to each other and crossed to provide a more compactconstruction. The inner end of each of the pulley-links extends througha slot 34 in web 26 of the body and is provided with a round terminal-36whereby it is pivotally connected to a longitudinally movableadjusting-collar mounted on Each of said collars comprises aninner-member 37, having a V shaped groove 39 for each link-end 36 and amember 38 alsoprovided with a V shaped groove 41 for each link-end andin said grooves the link-ends are pivotally held in such manner that theends will be moved longitudinally with the adjusting-collars to shiftthe adjusting-links 29 and 30, of the pulley positively and conjointly,inwardly and outwardly to vary the size of the rim. Member 38 isadjustably held by a follower 42, adjustably connected by a screw-threadto collar-member 37. Screws 44 secure the follower and member 38 in setrelation. Collar-member 37 is caused to revolve with the wheel-shaft a,by a key 45, which, however, permits longitudinal adjustment of thecollar to vary the size of the pulley. A trunnioncollar 47 mounted onfollower 42, is provided with a face 48 of anti-friction metal, such asBabbitt, for engaging one side of follower 42 and pins 49 for engagingthe other side of the follower, and trunnions 50, to which are connectedthe shifter-levers for operating the adjusting-collars to vary the sizeof the rim and for holding the collars in assigned positionlongitudinally.

In the operation of the pulley thus described, the rim-sections andsupportinglinks are guided in the body and driven thereby, and bylongitudinal shift of the adjustin -collars, all of the crossed links 29and 30 wil be conjointly o erated to move the rim-sections radiallyindependently or without shift of the wheel body and will holdthesections to form a rim or working-face of the desired diameter for abelt.

Usually in variable drive-mechanism, two of the variable pulleys areoperated together and the size of one pulley is increased and the otheris correspondingly decreased, so the mechanism can be continuouslyoperated without change of structure or variation of the belt. In Figs.1 to 5 is illustrated a driveanechanism which comprises pulleys A and Bof the construction hereinbefore described, and a belt C operativelyconnecting the pulleys so one will be driven from the other. Pulley A ismounted upon a shaft a, and pulley B is mounted upon a shaft 1). Both ofsaid shafts are mounted in bearings secured to a frame D of any suitableconstruction. The bodies of each of the pulleys are secured againstlongitudinal movement and to revolve with their respective shafts. Theshifting-mechanism for operating the adjusting-collars of wheel Acomprises levers 51 and 52, each having a bifurcated end connected totrunnions 50 of one of the collars 47. Said collars are respectivelyfulcrumed at 57 and 58 in brackets 59 and 60, respectively secured tocross-bars 61 and 62. The shifting-mechanism for pulley B compriseslevers 53 and 54, each of which is provided with a bifurcated endconnected to the trunnions 50 of collars 47 for said wheel and ispivoted at 55 in a fixed bracket 56 secured to a supporting-bar 77 whichis secured to the frame. The mechanism for adjusting the shifting-leverscomprises a hand-wheel 63 which serves as a crank and is secured to ashaft 64 which is provided with a worm 65 engaging a worm-wheel 66,secured to a camshaft 67, journaled in a bracket 69, secured tosupporting-bars 68. Cams 71 and 72 are secured to revolve with shaft 67and each has cam-surfaces adapted to shift and control two of theshifterlevers. Cam 72 is provided with a cam-surface 73, adapted toshift lever 54 and a cam-surface 7 4 for shifting lever 51. Cam 71 isprovided with a cam-surface 75 for shifting lever 52 and a cam-surface76 for shifting lever 53. By adjustment of hand-wheel 63 the cam-shaft67 can be revolved to simultaneously shift the shifter-levers for bothpulleys so that the size of the rims of the pulleys will be respectively increased and decreased. The wheelperipheries whencorrespondingly shifted, e. 9., to give the same aggregate diameter ofthe two pulleys, do not maintain tne belt and pulleys in drivingrelation because when the pulleys are of the same diameter the straightreach of the belt extends approximately from center to center of thepulleys and when the diameters of the peripheries are materiallydifferent the straight reach is less. In order to maintain properfrictional engagement at all times, despite variation of the diameter ofthe respective peripheries of the pulleys, earns 71 and 7 2 have theiredges formed to differentially operate the shifter-levers so that properfrictional contact between the belt and the pulleys will be maintained.Assuming the mechanism to be in the position illustrated in Figs. 1 and4, and it is desired to set the pulleys into position so the shafts willbe driven at the same speed, the cams will differentially adjust thepulleys so that i l'thsegzite of the diameters of the two pulleys willbe slightly greater than the aggregate of the diameters of the pulleyswhen these are in the position illustrated, to compensate for thedifferences aforesaid. These cams not only conjointly adjust the pulleysbut also effect dill'erential adjustment so frietional engagement of thebelt and the wheels will always be properly maintained. The radial shiftof the rim sections is dill'crential with respect to the longitudinalshift of the collars, because a greater shift of the collars isnecessary as the rim-sections approach their outward position, than whenthey are near their innermost position, and cams 71 and 72 are formed torectify this dill'erence and to properly shift the collars so theresultant shift of the rim-sections will retain the peripheries and beltin operative relation.

A throw-off mechanism is provided whereby the belt and pulleys can beshifted into and out of operative relation. anism also makes it possibleto adjust one of the pulleys to compensate for variation in belt length,resulting from stretching, wear or inaccurate fitting. The lever l'ulcra57 and 58 of the shifting-levers of one of the shifting-mechanisms aremovable to and from each other and are forced into position to keep thebelt taut. Bars 62 and 61 to which the fulcrum-supporting brackets 5)and 60 are respectively secured by bolts are slidably mounted inbrackets which are secured to the frame D. l lacl of the fulcrum-bars 61and 62 has rigidly secured thereto a bracket 80 in which is held aplunger 81, which is pressed. outwardly by a. stout spring 82. A screw83, adjusts the force of the spring to apply the desired force. A cam 84journaled in brackets 85, is secured to a shaft 86, having a crank 87whereby the shaft can be turned and a pawl and ratchet 88 for holdingthe shaft in assigned position. By adjustment of cam 84, greater or lesspressure will be supplied to the fulcrum-lmrs to force the pivots of theshifting leyers into position and so the adjusted rinnsections of wheelA will take up any slack in the belt. By shift of cam 84 the diameter ofpulley A can be varied so the belt will not be operated, and thus thismechanism can be. used as a throw-elf for pulleys It and B.

When it is desired to vary the speed of the driven shaft, the operator,by adjustment of hand-wheel 63 an simultaueously shift theadjusting-collars for both pulleys to which the supporting-levers areconnected, so the. rim-sections will be shifted to effect desiredvariation of speed and to maintain proper relative diameters so thebelt; will drive one pulley from the other. By o 'ieration ol' crank 87,cam 84- can be set. to compensate i This niechfor any slight variationin the length of the belt and can be used to disconnect and operativelyconnect the pulleys. It will be understood that one of the shafts, e.g., a, has power applied thereto in any well known manner and may beprovided with a drivewheel 85 and that either shaft may be used to driveany machine or mechanism.

The invention possesses several important advantages. It provides apulley in which the rim-sections are positively shifted inwardly andoutwardly by the adjustingmechanism, and also mechanism which makes itpossible to em loy a body secured to revolve with the sha't andagainst'longitudinal movement on the shaft. Furthermore, the sectionsand supports therefor are guided in the body and in such manner that asupplemental belt for securing the rimsections against outward movementis unnecessary. The invention also rovides improved mechanism forconjoint y adjusting a pair of pulleys and mechanism which effectsproper shift of the sections to maintain the belt and the pulleys inoperative relation. Furthermore, adjustment of the pulleys to start orstop the driven pulley, can be made without stopping the mechanism, anadvantage which is very important in drivingmechanism for certainpurposes, e. 9., in motor-vehicles.

The invention is not to be understood as restricted to the details ofconstruction set forth, but may be varied without departing from thespirit and scope of the invention, and features of the invention may beemployed severally without adoption in entirety, e. g., the improvedpulley, and can be used to advantage in instances where a pair ofvariable ulleys is not necessary.

Having thus described the invention, what I claim as new and desire tosecure by Letters Patent, is:

1.. In a variable pulley, the combination of a body having guidestherein, rim-sections adjustably sustained thereby, and mechanism foradjusting the sections comprising a pair of links for each sectionextending through the guides in said body.

2. In a variable pulley, the combination of a body having guidestherein, rim-sections adjustably sustained thereby, and mechanism foradjusting the sections comprising a pair of crossed links extendingthrough the guides in said body.

3. In variable drive-mechanism, the combination of a pair of pulleyscomprising adjustable rim-sections, a belt and mechanism whereby thesections will be differentially adjusted comprising a pair of levers,each having a fixed fulcrum for one of the pulleys and a pair of leverseach having an adjustable fulcrum for the other pulley.

4. In variable drive-mechanism the combination of a pair of pulleys,each comprising radially adjustable rim-sections, a belt,adjusting-mechanism for the sections comprising a cam for differentiallyadjusting the sections of one pulley with respect to those of the other,and means for shifting the cam.

5. In variable drive-mechanism, the combination of a pair of pulleys,each comprising radially adjustable rim-sections, a belt, and mechanismfor adjusting the sections comprising shifter-levers, a cam for shiftingthe levers, and means whereby the cam may be shifted.

6. In variable drive-mechanism, the combination of a pair of pulleys,each comprising radially adjustable rim-sections, a belt, and mechanismwhereby the sections will be differentially adjusted comprisingshifterlevers for each pulley, a cam, and means whereby the cam may beshifted.

7. In variable drive-mechanism, the combination of a pair of pulleyseach com rising radially adjustable rim-sections, a be t connecting thepulleys and mechanism for adjusting the sections comprising a pair ofcams whereby the sections of the pulleys will be difierentially adjustedwith respect to one another and mechanism for conjointly shifting saidcams.

8. In variable drive-mechanism, the combination of a pair of pulleyscomprising adjustable rim-sections, a belt, and mechanism for adjustingthe sections comprising a pair of levers, each having a fixed fulcrumfor one of the pulleys, and a pair of levers each hav- :ing anadjustable fulcrum for the other pul- 9. In variable drive-mechanism,the combination of a pair of pulleys comprising adjustable rim-sections,a belt, and mechanism whereby the sections will be adjusted comprising apair of levers each having a fixed fulcrum for one of the pulleys, apair of levers each having an adjustable fulcrum for the other pulley, acam, and means whereby the cam can be shifted.

10. In variable drive-mechanism, the combination of a pair of pulleyscomprising adjustable rim-sections, a belt, and mechanism for adjustingthe sections, comprising a pair of levers, each having an adjustablefulcrum, spring pressed means whereby the levers will be forced intoposition to keep the belt taut, and adj usting-mechanism whereby thefulcra can be shifted.

1 1. In variable drive-mechanism, the combination of a pair of pulleyscomprising adjustable rim-sections, a belt connecting the pulleys,mechanism for adjusting the rimsections, and a cam whereby saidmechanism ma be operated to release the belt.

12. n variable drive-mechanism, the combination of a pair of pulleyscomprising adjustable rim-sections, a belt, mechanism for adjusting thesections, comprising a pair of shifter-levers, each having a fixedfulcrum for one of the pulleys and a pair of levers each having anadjustable fulcrum for the other pulley, a cam for conjointly shiftingsaid levers, and means for forcing the levers having adjustable fulcrainto position to keep the belt taut.

13. In variable drive-mechanism, the combination of a pair of pulleyscomprising adjustable rimsections, a belt, mechanism whereby thesections may be adjusted, com prising a pair of shifter-levers eachhaving a fixed fulcrum for one of the pulleys and a pair of levers eachhaving an adjustable fulcrum for the other pulley, a cam for conjointlyshifting said levers, and spring pressed means for forcing the levershaving adjustable fulcra, into position to keep the belt taut.

14. In Variable drive-mechanism, the combination of a pair of pulleyscomprlsmg adjustable rim-sections, a belt, and mechanism for adjustingthe sections, comprising a pair of shifter-levers, a supporting-bar forthe fulcrum of each of said levers, and a yielding connection forforcing the fulcra into position. to keep the belt taut.

15. In variable drive-mechanism, the combination of a pair of pulleyscon'iprising ad justable rim-sections, a belt, and mechanism foradjusting the sections, comprising a pair of shifter-levers, a supmrtingdaar for the ful crum of each of the levers, and a yieldingconnection between the lovers, and means whereby the connection can beadjusted to shift the lever fulcra.

STEPHEN B. GRAY Witnesses J. WM. ELLsoN, C. A. Jonnson.

